Before we explain sleep apnea, let's quickly break down how breathing works. When you're awake, the muscles of your throat act to keep the airway straight and open so air can flow in and out of your lungs. When you sleep, these same muscles relax and your throat gets narrower. Normally, this doesn't close the airway, it just slows down breathing during sleep.
A male chicken under one year old is called a cockeral. A male chicken over a year old is called a cock, or rooster. A female chicken under the age of one is called a pullet. A female chicken over the age of one is called a hen. Not all chicks are hens. Chicks can be cockerals or pullets.
Cockerels follow strict pecking order on dawn calls: Most dominant roosters crow first to announce the arrival of morning. It is the sound that heralds the dawning of a new day, but it seems a cockerel's crow also reveals something about the pecking order in the farm yard. Biologists have discovered roosters follow a strict social order when announcing sunrise with their characteristic 'cock-a-doodle-do'.